“They are 100 percent engaged, but they were trying to keep it quiet,” a Hollywood source tells us.

The couple first met on the set of the hit HBO series in 2012 playing on-screen love interests but didn’t make their red-carpet debut until 2016 at the Olivier Awards.

“They’re yet to set a date, but told friends and family last week that they’ve got engaged,” a source told the Sun, who first broke the engagement news. “Kit’s known for ages he’s wanted to marry Rose but he wanted them to get a house and settle down a bit first. After moving in together in January, he felt it was the right time to take the next step.”

Kit Harington and Rose LeslieFilmMagic

In 2016, Harington, 30, opened up to Vogue Italia about how shooting in Iceland was his favorite “GoT” memory because it’s where he fell in love with Leslie, also 30.

“If you’re already attracted to someone, and then they play your love interest in the show, it becomes very easy to fall in love,” he said.

Reps for Leslie and Harington did not immediately return requests for comment.